I am stuck. I am trying to add a multiple time stamps to a google doc spreadsheet. I have figured out how to add a time stamp formula to a blank column. I created the script below:
function timestamp() {
return new Date()

And added the formula: =IF(ISBLANK(F3),,TIMESTAMP(F3)) to the column I wanted the time stamp to appear in, which works perfectly.

Now I am trying to add a time stamp formula based on a column with drop down boxes. I work at a doctors office and I want to know the exact time a physician places an order. I have created drop down boxes that are pre-populated with the most common orders.

Any help you can provide would be greatly appreciated. Please keep in mind that this is a google doc spreadsheet so iteration preferences cannot be changed. I have been at this for hours and cant seem to get it right. I have included the link below. The columns with the drop down boxes that the time stamps will be based off of are H, J, and L. The columns where the time stamp should appear are I, K, and M.